In this type of two-slat unit, the suspension elements are placed above the long sides of the frame, and are therefore visible. In general, the suspension element presents elastic walls that extend parallel to the slats.
The outside ends of these walls are therefore visible, where the term “outside” is used relative to the frame of the bed base, and a person making a bed (in the sense of putting sheets and blankets into place) can trap the fingers in the channels defined by the elastic walls. In addition, this disposition of the suspension walls gives rise to problems in preventing the slats from pivoting about their own axes.